Bhadrak Engineering School & Technology BEST Asurali,Bhadrak Official

12/09/2019

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23/06/2018

1. Explain the second law of thermodynamics.

The entropy of the universe increases over time and moves towards a maximum value.

2. What kinds of pipes are used for steam lines?

Normally galvanized pipes are not used for steam. Mild steel with screwed or welded fittings are the norm. Pressure and temperature are very important factors to be considered in what type of materials to be used. Steam even at low pressures can be extremely dangerous.

3. What is the difference between shear center flexural center of twist and elastic center?

The shear center is the centroid of a cross-section. The flexural center is the center of twist, which is the point on a beam that you can add a load without torsion. The elastic center is located at the center of gravity. If the object is homogeneous and symmetrical in both directions of the cross-section then they are all equivalent.

4. What is ferrite?

Magnetic iron rock

5. What is the difference between projectile motion and a rocket motion?

A projectile has no motor/rocket on it, so all of its momentum is given to it as it is launched. An example of a projectile would be pen that you throw across a room.
A rocket or missile does have a motor/rocket on it so it can accelerate itself while moving and so resist other forces such as gravity.

6. What is a cotter joint?

These types of joints are used to connect two rods, which are under compressive or tensile stress. The ends of the rods are in the manner of a socket and shaft that fit together and the cotter is driven into a slot that is common to both pieces drawing them tightly together. The tensile strength of the steel is proportionate to the strength needed to offset the stress on the material divided by the number of joints employed.

7. What is the alloy of tin and lead?

A tin and lead alloy is commonly called solder. Usually solder is a wire with a rosin core used for soldering. The rosin core acts as a flux.

8. What does F.O.F. stand for in piping design?

FOF stands for Face of Fl**ge. A fl**ge has either of the two types of faces:
a) Raised face
b) Flat face
The F.O.F is used to know the accurate dimension of the fl**ge in order to avoid the minute errors in measurement in case of vertical or horizontal pipelines.

9. Explain Otto cycle.

Otto cycle can be explained by a pressure volume relationship diagram. It shows the functioning cycle of a four stroke engine. The cycle starts with an intake stroke, closing the intake and moving to the compression stroke, starting of combustion, power stroke, heat exchange stroke where heat is rejected and the exhaust stroke. It was designed by Nicolas Otto, a German engineer.

10. What is gear ratio?

It is the ratio of the number of revolutions of the pinion gear to one revolution of the idler gear.

11. What is annealing?

It is a process of heating a material above the re-crystallization temperature and cooling after a specific time interval. This increases the hardness and strength if the material.

12. What is ductile-brittle transition temperature?

It is the temperature below which the tendency of a material to fracture increases rather than forming. Below this temperature the material loses its ductility. It is also called Nil Ductility Temperature.

13. What is a uniformly distributed load?

A UDL or uniformly distributed load is a load, which is spread over a beam in such a way that each unit length is loaded to the same extent.

14. What are the differences between pneumatics and hydraulics?

a) Working fluid: Pneumatics use air, Hydraulics use Oil
b) Power: Pneumatic power less than hydraulic power
c) Size: P components are smaller than H components
d) Leakage: Leaks in hydraulics cause fluid to be sticking around the components. In pneumatics, air is leaked into the atmosphere.
e) Pneumatics obtain power from an air compressor while hydraulics require a pump
f) Air is compressible, hydraulic oil is not

15. What is enthalpy?

Enthalpy is the heat content of a chemical system

16/10/2017

If the door of a running refrigerator in a closed room is kept open, what will be the net effect on the room?
A
it will cool the room
B
it will heat the room
C
it will make no difference on the average
D
it will make the temperature go up and down

09/09/2017

30/08/2017

Tool geometry

15/04/2017

At the end of each semester, students are given forms to express their views regarding the classes,

06/01/2017

For a job, register your name in the cpc cell.web site www.cpcdtet.nic.in for more, call Mr S.k Das t&p officer ,Best,Asurali.

02/03/2016

MECHANICAL INTERVIEW QUESTIONS :

1. What is the difference between scavenging and supercharging ?

Ans: Scavenging is process of flushing out burnt gases from engine cylinder by introducing fresh air in the cylinder before exhaust stroke ends. Supercharging is the process of supplying higher mass of air by compressing the atmospheric air.



2. What are the names given to constant temperature, constant pressure, constant volume, constant internal energy, constant enthalpy, and constant entropy processes.Ans: Isothermal, isochroic, isobaric, free expression, throttling and adiabatic processes respectively.



3. In a Rankine cycle if maximum steam pressure is increased keeping steam temperature and condenser pressure same, what will happen to dryness fraction of steam after expansion ?Ans: It will decrease.



4. Why entropy change for a reversible adiabatic process is zero ?

Ans: Because there is no heat transfer in this process.



5. What are two essential conditions of perfect gas ?

Ans: It satisfies equation of state and its specific heats are constant.



6. Enthalpy and entropy are functions of one single parameter. Which is that ?

Ans: Temperature.



7. Why rate of condensation is higher on a polished surface compared to rusty surface ?

Ans: Polished surface promotes drop wise condensation and does not wet the surface.



8. How much resistance is offered to heat flow by drop wise condensation ?

Ans: Nil


9. What is the relationship between COP of heating and cooling ?

Ans: COP of heating is one(unity) more than COP of cooling.



10. How much is the work done in isochoric process ?

Ans: Zero.



11. When maximum discharge is obtained in nozzle ?

Ans: At the critical pressure ratio.



1. Under what condition the work done in reciprocating compressor will be least ?

Ans: It is least when compression process approaches isothermal. For this purpose, attempts are made to cool the air during compression.



13. What is the difference between stalling and surging in rotary compressions ?

Ans: Stalling is a local phenomenon and it occurs when How breaks away from the blades. Surging causes complete breakdown of flow and as such it affects the whole machine.



14. Why the electric motor of a fan with backward curved blades is never got overloaded under any condition ?

Ans: The maximum power is consumed at about 70% of maximum flow in case'of fan with backward blades. For higher flow, power consumption gets lower.



15. Why the work per kg of air flow in axial flow compressor is less compared to centrifugal compressor for same pressure ratio ?

Ans: Isentropic efficiency of axial flow compressor is higher.



16. What is the name given to portion of thermal energy to be necessarily rejected to environment ?

Ans: Anergy.



17. What is pitting ? How it is caused ?

Ans: Non uniform corrosion over the entire metal surface, but occuring only in small pits is called pitting. It is caused by lack of uniformity in metal.



18. What is caustic embrittlement ?

Ans: It is the actual physical change in metal that makes it extremely brittle and filled with minute cracks. It occurs particularly in the seams of rivetted joints and around the rivet holes.



19. Which impurities form hard scale and which impurities soft scale ?

Ans: Sulphates and chlorides of lime and magnesium form hard scale, and carbonates of lime and magnesium form soft scale.



20. What is the difference between hard water and soft water ?

Ans: Hard water contains excess of scale forming impurities and soft water contains very little or no scale forming substances.



21. Which two elements in feed water can cause corrosion of tubes and plates in boiler ? '

Ans: Acid and oxygen in feed water lead to corrosion.



22. What should be done to prevent a safety valve to stick to its seat ?

Ans: Safety valve should be blown off periodically so that no corrosion can take place on valve and valve seat.



23. Why large boilers are

28/09/2014

4th Semester(Regular) result publish,

15/08/2014

Happy independence day to all student

06/08/2014

College is open on 11th aug.